This invention relates to an improved axial pin tumbler lock and key assembly wherein the key includes detents on the inside of the cylindrical key barrel and projecting ribs on the outside of the barrel. The lock is an axial pin tumbler lock which may have multiple combinations.
Various prior art patents disclose axial pin tumbler locks. Among those is U.S. Pat. No. 4,233,828 which is incorporated herewith by reference. Some axial pin tumbler locks have the capability to change the key combination so that any one of a number of various keys may be utilized with a single lock, and the particular key to be used may be altered or changed by use of a change key. Such locks usually utilize a key which includes a hollow cylinder having detents along the outside edge or surface of the tube. The detents engage cylindrical axial pin tumblers which positioned within a rotating barrel retained within the housing of the lock.
The key change lock referenced in the prior art patent, incorporated herewith by reference, is commercially useful but such a lock has features which require that the lock have an axial length or extent which may, on certain occasions, be undesirable. That is the axial length of such a lock may be too great for certain applications. For that reason, among others, the present lock was developed. The lock construction of the invention maintains the capability to provide multiple key combinations in a single lock and also provides the advantage of having a lesser or dimished axial length relative to prior axial pin tumbler lock constructions. The invention is useful in key change and single key axial pin tumbler locks.